1. Field of Invention
This invention relates to chimney dampers and chimney caps. More particularly, this invention relates to an improved chimney cap which uses a combination spring mechanism contained within closed slidable tubes to bias the chimney damper to an open position while also permitting the cap to be pulled to a closed position.
2. Prior Art
In homes and other buildings having a fireplace, the fireplace opening is connected to a chimney flue which is open to the outside of the building. When in use, the combustion products from the fireplace pass up through the flue and exit the chimney in a conventional fashion.
When the fireplace is not in use, however, the fireplace opening and chimney flue form a passage through which heat can escape from the interior of the building. Although most fireplaces contain conventional fireplace dampers at the bottom of the flue or immediately above the fireplace opening, these fireplace dampers do not usually provide an adequate seal to prevent heat loss through the chimney flue.
A number of different types of chimney dampers or chimney caps have been produced which are mounted on the top of the chimney to provide a better seal and thus reduce the amount of heat lost through the chimney flue. For example, one well known type of chimney damper is a cap-type flue damper as shown in U.S. Pat. Nos. 5,437,574, 5,387,151, 5,295,901, 5,125,869, 4,554,863, 4,181,119 and 4,020,754.
Another common type of chimney damper utilizes a lid attached to the side of the chimney by hinges, which lid closes the flue as shown, for example, in U.S. Pat. No. 4,368,663.
Another common type of chimney damper utilizes a frame secured to the top of the chimney containing a flap which is pivotally attached to the frame. This flap both closes the flue and prevents substantial quantities of either air or water from flowing over the damper flap into the chimney when the flap is in a closed position. See the particularly preferred devices shown in U.S. Pat. Nos. 3,945,307, 5,127,874 and 5,160,291.
Many chimney dampers also contain springs or other similar devices which may orient the chimney damper to an open position. See, for example, U.S. Pat. Nos. 3,101,039, 3,267,832, 3,945,307, 4,020,754, 4,181,119, 4,007,730, 5,094,050, 4,554,863, 5,125,869, 5,295,901 and 4,368,663.
A common problem that arises with conventional chimney dampers is a buildup of soot or creosote on the components of the chimney damper. This problem was addressed, for example, by the device disclosed in U.S. Pat. No. 4,554,863. In this device a spring is utilized to bias the chimney damper to an open position. The spring is secured between a bracket and the top portion of the chimney damper.
Another problem often encountered with complicated chimney damper systems is a reduction in the flow of air through the chimney because of the presence of numerous components of conventional chimney damper system.
Accordingly, it is an object of this invention to provide a chimney damper and cap system containing means to bias the chimney cap to an open position.
It is a still further object of the invention to provide a chimney damper and cap system containing a multiple spring system designed to bias the chimney cap to an open position.
It is a still further object of this invention to provide a chimney damper and cap system containing a closed, slidable tubular support system which supports the chimney cap when that the chimney damper and cap system is either closed or open.
It is a still further object of this invention to disclose a chimney damper and cap system containing a bracket to support a slidable tubular support system which reduces the restriction on flow of air through the chimney and the chimney damper and cap system.
It is an additional object of the invention to provide a chimney damper and cap system which utilizes a multiple spring system to bias the cap to an open position, which spring system is placed within a slidable tube system which reduces the exposure of the spring system to soot and creosote produced by fires in the chimney.
These and other objects are produced by the improved chimney damper and cap system of the instant invention.